/Engine/Plugins/Runtime/RigVM/Source/RigVMDeveloper/Public/RigVMCompiler/RigVMAST.h
An abstract syntax tree external variable expression represents the reference of unowned / external memory.
class FRigVMExternalVarExprAST : public [FRigVMVarExprAST](API\Plugins\RigVMDeveloper\RigVMCompiler\FRigVMVarExprAST)